1. Field of Invention
The present invention pertains to the field of medical imaging. More particularly, the present invention is a rail system for supporting and moving a patient gantry, wherein a portion of the rail system is removable to reduce a tripping hazard when not in use.
2. Description of the Related Art
In the field of medical imaging, it is becoming more common to combine the images obtained from multi-modality scans in order to accomplish a more accurate image of a patient. For example, U.S. Pat. No. 6,490,476 issued on Dec. 3, 2002, to D. W. Townsend et al., discloses a combined PET and X-ray CT tomograph and method for using same. As discussed by Townsend et al., the role of PET imaging in oncology research and patient care is growing, and the ability of PET to add unique functional information to that obtained by conventional anatomical-based modalities, such as CT and magnetic resonance (MR), is generating considerable interest. The discussion of the background art in the '476 patent is incorporated herein by reference.
In recent years, there has been considerable progress in the development of techniques to co-register and align functional and anatomical images. This has been driven primarily by the demand for accurate localization of cerebral function visualized in PET studies where the low resolution morphology is, in most cases, insufficient to identify the related cerebral structures. After two images from different modalities are aligned they can be displayed in a number of ways, such as, for example, side by side with linked cross-hair cursors, so that positional correspondence between the two image sets is easily established.
The '476 device is directed to an X-ray CT and PET tomograph having a physically known relationship one with the other. Each of the X-ray CT and PET tomograph are configured for use with a single patient bed such that a patient may be placed on the bed and moved into position for either or both of an X-ray CT scan and a PET scan. In one embodiment, X-ray CT and PET tomograph detectors are disposed in separate gantries which are fixed relative to each other, and wherein the patient bed is movable between the gantries. In another embodiment, the X-ray and PET tomograph detectors are disposed in separate gantries, either of which is movable with respect to the other.
One problem that arises with these configurations is servicing the imaging devices. With the two devices situated next to each other, the rearward device must be pulled away from the forward device in order to service the forward device. The current method used to pull the PET device from the CT device includes permanently mounting a bearing plate in the floor and using a winch to pull the PET device along the bearing plate. Thus, moving the PET device is a complicated task.
In addition to servicing the imaging devices, as disclosed by Townsend et al., moving the imaging devices is in some situations necessary for acquiring images. While the devices may be mounted on wheels, a specific path must be defined through which the imaging device travels in order to accurately position the imaging devices to acquire images that can be co-registered with minimal correction.